DB errors, is it the host or WP?

Okay, we just upgraded, and no more MySQL errors — but plenty of DB-related ones:

This set was generated by an attempt to post something I wrote before the upgrade:

WordPress database error: [Access denied for user: ‘dbo159687748@%’ to database ‘db159687748’]
INSERT INTO wp_postmeta (post_id,meta_key,meta_value) VALUES (‘865′,’_pingme’,’1′)

WordPress database error: [Access denied for user: ‘dbo159687748@%’ to database ‘db159687748’]
INSERT INTO wp_postmeta (post_id,meta_key,meta_value) VALUES (‘865′,’_encloseme’,’1′)

WordPress database error: [Access denied for user: ‘dbo159687748@%’ to database ‘db159687748’]
INSERT INTO wp_options (option_name, option_value, option_description, autoload) VALUES (‘cron’, ‘a:2:{i:1182708993;a:1:{s:8:\”do_pings\”;a:1:{s:32:\”40cd750bba9870f18aada2478b24840a\”;a:2:{s:8:\”schedule\”;b:0;s:4:\”args\”;a:0:{}}}}s:7:\”version\”;i:2;}’, ”, ‘yes’)

Warning: Cannot modify header information – headers already sent by (output started at /homepages/33/d157690626/htdocs/dsc040002073/wp-includes/wp-db.php:133) in /homepages/33/d157690626/htdocs/dsc040002073/wp-includes/pluggable.php on line 331

And this is the set generated when I tried to post a new test message:

WordPress database error: [Access denied for user: ‘dbo159687748@%’ to database ‘db159687748’]
INSERT IGNORE INTO wp_posts (post_author, post_date, post_date_gmt, post_content, post_content_filtered, post_title, post_excerpt, post_status, post_type, comment_status, ping_status, post_password, post_name, to_ping, pinged, post_modified, post_modified_gmt, post_parent, menu_order, post_mime_type) VALUES (‘3’, ‘2007-06-24 13:26:03’, ‘2007-06-24 18:26:03’, ‘DBO errors are so much fun’, ”, ‘wp test #2a’, ”, ‘publish’, ‘post’, ‘open’, ‘open’, ”, ‘wp-test-2a’, ”, ”, ‘2007-06-24 13:26:03’, ‘2007-06-24 18:26:03’, ‘0’, ‘0’, ”)

WordPress database error: [Access denied for user: ‘dbo159687748@%’ to database ‘db159687748’]
INSERT INTO wp_post2cat (post_id, category_id) VALUES (‘0’, ‘1’)

WordPress database error: [Access denied for user: ‘dbo159687748@%’ to database ‘db159687748’]
INSERT INTO wp_postmeta (post_id,meta_key,meta_value) VALUES (‘0′,’_pingme’,’1′)

WordPress database error: [Access denied for user: ‘dbo159687748@%’ to database ‘db159687748’]
INSERT INTO wp_postmeta (post_id,meta_key,meta_value) VALUES (‘0′,’_encloseme’,’1′)

WordPress database error: [Access denied for user: ‘dbo159687748@%’ to database ‘db159687748’]
INSERT INTO wp_options (option_name, option_value, option_description, autoload) VALUES (‘cron’, ‘a:2:{i:1182709563;a:1:{s:8:\”do_pings\”;a:1:{s:32:\”40cd750bba9870f18aada2478b24840a\”;a:2:{s:8:\”schedule\”;b:0;s:4:\”args\”;a:0:{}}}}s:7:\”version\”;i:2;}’, ”, ‘yes’)

WordPress database error: [Access denied for user: ‘dbo159687748@%’ to database ‘db159687748’]
INSERT INTO wp_usermeta ( user_id, meta_key, meta_value ) VALUES ( ‘3’, ‘wp_autosave_draft_ids’, ‘a:1:{i:-1182708977;i:0;}’ )

Warning: Cannot modify header information – headers already sent by (output started at /homepages/33/d157690626/htdocs/dsc040002073/wp-includes/wp-db.php:133) in /homepages/33/d157690626/htdocs/dsc040002073/wp-includes/pluggable.php on line 331

—-

So, is this a hosting error? Or is it a problem with upgrading DB permissions? Or something else?

Oddly enough, I *was* able to post one test message after we upgraded — although it did give rise to similar error messages to those above when I posted it in Safari, I was able to view it in Firefox. But when I tried a second test message, it was no go. Error messages, yes, test post #2, nope.

Another odd thing: I am receiving emailed trackbacks for every article I ever posted. Up to 277 of ’em so far!